How to Treat (and Prevent!) Heat Rash So You Can Stay Cool and Comfy All Summer

Photo credit: DjordjeDjurdjevic - Getty Images
Photo credit: DjordjeDjurdjevic - Getty Images


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This article was medically reviewed by Mona Gohara, M.D., a dermatologist and member of the Prevention Medical Review Board.

When the sweltering temps roll around, your body naturally tries to stay cool by sweating. But beyond feeling uncomfortably damp and hot, that sweat can bring on some gnarly side effects if it gets bad enough. Cue the heat rash. These painful patches of skin can show up all over your body, so we chatted with dermatologists to determine what is heat rash and exactly how to get rid of heat rash quickly using treatments that actually work.

What is heat rash?

Heat rash is a type of inflammation that occurs as a result of blocking the sweat ducts and often occurs in hot, humid environments or when someone has a high fever, says Marisa Garshick, M.D., a leading board-certified dermatologist at Manhattan Dermatology and Cosmetic Surgery and advisor of BioRepublic.

The true medical definition of a heat rash is a condition called miliaria, but people often use the phrase “heat rash” to refer to any rash that occurs in the summer after heat exposure, says Gary Goldenberg, M.D., a cosmetic and medical dermatologist at Goldenberg Dermatology in New York City.

What does heat rash look like and what are heat rash symptoms?

The tell-tale signs of heat rash are typically itching or a stinging sensation that persists, Dr. Garshick says. They appear as small, red bumps that look like little blisters and typically pop up on your back or other obstructed areas of the body, she notes.

Ife J. Rodney, M.D., founding director of Eternal Dermatology + Aesthetics in Maryland, says you may notice the following symptoms:

  • Bumps

  • Itchiness

  • Redness

  • Pain from underlying pustules

The bumps from heat rash can be itchy or prickly, Dr. Goldenberg says, which is why heat rash is sometimes called “prickly heat.”

Distinguishing heat rash from other rashes is difficult since it can look like several skin conditions that tend to flare up in the summer, like eczema or hives. However, these conditions are “usually much more itchy” than true heat rash, Dr. Goldenberg says.

Dr. Garshick explains that, unlike heat rash, traditional hives tend to appear as broader, light pink patches that come and go within 24 hours. Another common skin irritation called eczema is often pink with flaky patches that involve the arms and the area behind the knee.

“You can look for small blisters and redness on the extremities or areas that are prone to sweat,” Dr. Rodney says. However, if a rash you’ve never seen before pops up in the summer and it’s accompanied by a fever, is painful, or uncomfortable, it’s best to see your dermatologist for a proper diagnosis, Dr. Garshick says.

What are the different types of heat rash?

The different types of heat rash are broken down by how deep the blocked sweat ducts are, says Dr. Rodney.

Miliaria crystalline

This is the mildest form of heat rash, and it impacts the sweat ducts in the top layer of the skin. It causes clear, fluid-filled blisters and bumps that break easily. “Superficial heat rashes show up on areas where sweat is common like the head, neck, and upper torso,” Dr. Rodney says.

Miliaria rubra

This form of heat rash goes deeper into the skin and causes red bumps and itching or prickling in the affected area. “Sometimes, the red rash is accompanied by pustules,” Dr. Rodney says, pointing out that these are more common on the torso, between skin folds, or parts of the body where fabric tends to cause skin chafing, like the thighs.

Miliaria profunda

This is a less common form of heat rash that impacts the deeper layer of skin (called the dermis). “It happens mainly in tropical climates,” Dr. Rodney says. With miliaria profunda, sweat leaks out of the sweat gland into the skin, causing firm, skin-colored bumps on the arms, legs, and torso.

How to get rid of heat rash quickly and treatments

Heat rash will usually go away on its own, Dr. Goldenberg says, but there are a few things you can do to get relief if you’re uncomfortable.

✔️ Get out of the heat. “Heat rashes tend to go away with a change in environment,” Dr. Rodney says. That includes removing yourself from the heat if you can and moving into an air-conditioned space. Dr. Garshick adds that heat rash will typically heal by cooling the skin, keeping it dry, and avoiding exposure to heat.

✔️ Apply a topical steroid cream. If you’re especially itchy, Dr. Goldenberg recommends applying a topical steroid cream like 1% hydrocortisone to tamp down inflammation. It’s essential you don’t scratch at the rash, Dr. Garshick says, so she recommends applying a soothing lotion like CeraVe Moisturizing Lotion for Itch Relief or Sarna Original Anti-Itch Lotion.

✔️ Cool off. If you have miliaria rubra, Dr. Rodney says that using a cold compress on your skin may provide relief. Taking a cold bath or shower or adding fans or air conditioners to the space can also help, Dr. Garshick says.

✔️ Avoid irritants. Dr. Garshick suggests avoiding irritants, like fragrance when the skin is already sensitive.

All of this, along with doing your best to stay cool, should do the trick, Dr. Goldenberg says. However, there is a small chance that you can develop a bacterial infection from heat rash (avoid scratching!), which would lead to inflamed and itchy pustules. If that happens, call your doctor as you may need antibiotics to clear things up.

How to prevent heat rash

“With heat rashes, prevention works more than cure,” Dr. Rodney says. So how exactly can you prevent prickly heat? Limiting how much you sweat will help, the American Academy of Dermatology says, but obviously, that can be tricky in the summertime. Try these tips to prevent heat rash in the future.

✔️ Avoid tight clothing. “If you’re prone to heat rashes, avoid tight clothing or clothing made of fabrics like spandex, especially in the summer. Stick to breathable fabrics,” like cotton, Dr. Rodney says.

✔️ Stay hydrated. Dr. Garshick says staying hydrated in the heat can help keep you cool overall.

✔️ Keep yourself dry. Take special care to ensure areas that are more prone to moisture, like armpits or groin, are dry to avoid any rashes, says Mamina Turegano, M.D., F.A.A.D., a triple board-certified dermatologist, internist, and dermatopathologist and c-founder of Skintap.

✔️ Adjust fitness trackers. These tight devices, like wristbands and rings, can trap a lot of heat and sweat. Dr. Garshick suggests ensuring your device fits properly, picking a breathable fabric that won’t trap moisture, keeping the skin clean and moisturized, and removing devices after prolonged wear to avoid a rash.

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